Good evening. It's the story that is going on tonight as residents in one florida town are afraid to go to sleep in their own beds, for fear a sink hole can swallow them up. First a different worry. What if it doesn't lay underneath your home, but instead, down the block. The neighbors from hell. Matt gutman on the neighbors you don't want near your home. Reporter: The says goes, 6 that "good fences make good ighbors." But how do you build a fence high enough to shield you from this kind of behavior? Or this, as seen in this local news piece? How many fires in your house? Nut job! Reporter: Kathy hesterberg says her family had been living peacefully in this suburb outside st. Louis for 30 years. That was until last fall when a s.W.A.T. Team descended on her next door neighbor's home. Suspecting drugs. They were going in between the houses. Reporter: The man they were looking for -- 48-year-old greg jennings, the owner of a local tree trimming business. He blamed you? He put the blame on my mom. Reporter: Says she tipped off police. She tipped off an officer down the block. Reporter: Starting that day, he became belidge rant and bizarre. And deer carcasses. You never knew what you were going to come to. Reporter: So she installed security cameras to document. Night after night after night to prance around out there, on the property line. Each night, his behavior got more erratic. Reporter: The cameras are in plain sight. You figure they had a deterrent. But according to cathy that is greg, in the middle of the night, strolling the ground, in his underwear, and here, wearing a box on his head. So what should do you if you have a nasty neighbor? Calling the police all the time, they are getting the reaction they want. They are going to keep doing it. Reporter: What do you do if not even the police with help you? Cathy said she called them dozen of time. We can't do anything but try to mediate between the parties. Reporter: It's a fine line between a nuisance and ending up in handcuffs. The law, they don't help victims. It covers bullies. Reporter: Would you say he is a bully? Oh, yeah. Reporter: And that can help says shark tank's barbara. She knows real estate. You have to live with them for four or five years and when you have to sell your home, you have to disclose it. So the damage to your home is e nor rouse. Reporter: Since that media attention -- are you being a punk right now. Reporter: Cathy says they are working to the truce. And we wanted to talk to greg jennings and left a letter. It took a few attempts. I wanted to hear your side of the story, sir. Before he finally responded. Ly call the police. Reporter: I will leave your property. Safely leave our property right now. Go away! We are calling the police! Reporter: We left the property but he had called the police. He had just been slapped with felony drug charges. And in florida, he is making his neighbor's lives a bed of thorns. That is his house? That is right. Reporter: Francisco says his feud with this man started two years ago. Torres had fired him as his landscaper. Big mistake. So torres says he installed a $70,000 security system. He even quit his job to monitor it full time, hoping to catch him red handed. Witness what he says is the ultimate landscaper revenge. Watch the white struck driving by the lawn. A mystery liquid squirts out of the window. I had says the grass died suddenly and never grew back. There is so much poison, there is no way for them to grow. Reporter: And exhibit "b," the dogs and a frat house classic, throwing eggs at the house. And those are nailed catapulted from his truck to the drive way. He hurled rocks. where two different men smashed his car windows, but he has not implicated. After calling police 40 times this year, he was finally with a retraining order. And he is currently awaiting trial. We decided to try to ask him why he has such hostility to the neighbor. Hi, I am matt gutman from and. No. Reporter: Your neighbors say you have been terrorizing them. I wonder if you are answers for them. You're backing out? in he says he is also a victim in the neighborhood feud. What is the best recourse? When you get to the point where you tried reasoning and being friendly, you have done everything. If you need to fight fire with fire and you can do it in a socially responsible, lawful manner, I say go for it. Reporter: For this south florida community, peace may only come after they had their day in court.

This transcript has been automatically generated and may not be 100% accurate.

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{"id":18689888,"title":"Neighbors From Hell","duration":"6:55","description":"Confronting a Florida man who allegedly harassed his neighbors with eggs, rocks and fire.","url":"/2020/video/neighbors-hell-18689888","section":"2020","mediaType":"Default"}